China said Thursday it would offer $20 billion in new loans to Africa, underscoring the relationship’s growing importance, as Chinese companies agreed to operate more responsibly on the resource-rich continent.

Beijing has poured money into Africa over the last 15 years, seeking to tap into its vast natural resources, and China became the continent’s largest trading partner in 2009.

But its aggressive move into the continent has at times caused friction with local people, with some complaining Chinese companies import their own workers, flout labour laws and mistreat local employees.

Addressing African leaders including South African President Jacob Zuma and Kenya Premier Raila Odinga, President Hu Jintao said the loans would focus on supporting infrastructure, manufacturing and the development of small businesses.